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Reduce gas use without confusing it with rate savings in Illinois

DOE’s boiler purchasing guidance considers building efficiency, equipment sizing and lifecycle costs. Apply that method to the actual equipment and load; it does not establish a universal replacement payback or a local rebate.

Reviewed October 16, 2026

By Commercial Gas Rates editorial team · Educational guidance; verify account-level terms.

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Illinois: Measure consumption before attributing savings

Start with DOE FEMP: boiler purchasing, sizing and lifecycle analysis. The table below links this decision to the represented gas companies in Illinois. It does not establish service or supplier availability for every account.

Build the operating baseline

Record actual billing periods, estimated readings, operating hours and occupancy or production. Separate space heating from process and hot-water use where the available data permits. Explain changes before comparing periods.

Reconcile engineering and procurement

Have qualified personnel evaluate controls, equipment and service capacity. Update the contracted volume forecast after a project and review tolerance or minimum-volume terms. Verify program eligibility and preapproval before treating an incentive as funded.

Illinois utility application

Gas service companyContract component to revisit after load reductionPrimary reference
Nicor GasUtility supply benchmark versus AGS supply and recurring fees, keeping delivery separateOfficial program / tariff
Ameren IllinoisApplicable utility gas supply and delivery components; incremental transport costs if eligibleOfficial program / tariff
Peoples GasUtility supply benchmark versus AGS supply and recurring fees, keeping delivery separateOfficial program / tariff
North Shore GasUtility supply benchmark versus AGS supply and recurring fees, keeping delivery separateOfficial program / tariff
MidAmerican EnergyState-specific gas supply and delivery componentsOfficial program / tariff

Nicor Gas: the program detail behind this decision

The ICC identifies Nicor Gas, Peoples Gas and North Shore Gas for residential and small-commercial Gas Choice. An Alternative Gas Supplier sells supply while the delivery utility remains. The ICC’s utility list does not establish that every supplier accepts every commercial class or offers a suitable contract. Program Illinois.

Apply the evidence to an account file

After reducing forecast consumption, revisit Utility supply benchmark versus AGS supply and recurring fees, keeping delivery separate. Ask whether the revised operating load changes The named delivery company and its eligible small-commercial service class or any conditions associated with Supplier registration, cancellation terms and return-to-utility conditions.

Worked check: fixed charges do not fall with every therm

Assume hypothetical use of 10,000 therms at a constant $0.80 supply price and a $30 monthly supply fee. Modeled supply cost is $8,360. If use falls ten percent to 9,000 therms with the same price and fee, the total becomes $7,560: an $800 reduction, or about 9.57 percent of that supply total. This excludes delivery, taxes and project costs and proves no equipment result. The illustration shows why a percentage therm reduction is not automatically the same percentage dollar reduction.

Turn the review into a calculation

Build a monthly weighted budget. Enter documented assumptions in matching energy units. Keep any charge outside both supply offers separate; the result does not establish eligibility or an available quote.

Read the Illinois utility guide for the wider service-company distinctions. Convert billed gas units using the bill’s heat-content factor when moving from volume to energy.

Sources and review notes

Reviewed October 16, 2026. Program information can change. Confirm the effective utility tariff, supplier availability and written offer before proceeding. Examples and planning tools are educational; they are not executable quotes or verified customer results.

A practical next step

Put the full contract in view.

Ask about your utility, supply terms or renewal. Keep account numbers and documents out of the initial inquiry.

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